Abrams Planetarium Comet Hyakutake Diary

Abrams Planetarium Comet Hyakutake Diary

Thursday, March 21
Comet Hyakutake already glows brighter than 2nd
magnitude, and it's visible late evening through rest of night. Four
hours after sunset, locate Big Dipper high in NE; its curved handle leads
you to bright Arcturus in the east: "Follow the arc to Arcturus." Look
for a fuzzy ball of light about 10 degrees below Arcturus. (Ten degrees
is about the width of your fist held with your arm fully extended.)
Binoculars may show the tail as a faint fan. The comet is now 13.4
million miles from Earth and closing!

Friday, March 22
Three or four hours after sunset, locate Arcturus in
east (see March 21), and the 2nd-magnitude star Izar 10 degrees to its
left. Tonight comet may be a first magnitude fuzzball 9 degrees lower
left of Arcturus and within 3 degrees lower right of Izar. Binoculars
give the best view. Arcturus, Izar, and four additional stars to the left of
Arcturus complete a kite-shaped figure lying on its side, comprising the
constellation Bootes, the Herdsman. Tonight it's easy to note the
comet's motion against background stars, exceeding 0.5 degree (one
Moon's width) per hour. At 3:30 a.m. EST Saturday morning, the
comet's center passes 0.4 degree E of Izar, and the star will shine
through the outer coma or dusty extended atmosphere of the comet.
Viewing at MSU Observatory, Fri. & Sat. 9:15-11:00 p.m. if sky is
clear.

Saturday, March 23
Comet is 30 degrees up in ENE within 3 hours
after sunset. Look 20 degrees upper left of Arcturus and 15 degrees
lower right of the end of Big Dipper's handle. The comet is near the
northern end of the kite-shaped figure of Bootes (see chart). Watch
comet drift outside the kite as hours pass. The comet shifts 18 degrees
daily for next two days as it sweeps past Earth. About 3 hours 22
minutes before sunrise on Sunday, comet passes directly over northern
U.S. [In Lansing, MI, that's at 3:11 a.m. EST.]

Sunday, March 24
At nightfall, the comet is already well up in the NE
and about 10 degrees from the last two stars at the end of the handle of
the Big Dipper. Early this week, Comet Hyakutake is predicted to reach
its greatest brightness, between zero and first magnitude, but because
much of its light is spread out over a large area, the "coma", or head of
the comet, it will not seem as bright as a star of the same magnitude.
Late tonight (at 2 a.m. EST Monday), the comet passes only 9.5 million
miles from Earth, while appearing to move nearly 0.8 degree (1-1/2
Moon's-widths) per hour.

At nightfall, locate the Little Dipper in the north.
Kochab is the brightest star in the bowl of the Little Dipper, 17 degrees
from and equal in brightness to Polaris, the North Star, at end of the
Little Dipper's handle. Early tonight, the comet appears about 3 degrees
upper right of Kochab. Overnight, watch changing alignment of comet
with the two bright "Guardians of the Pole" in Little Dipper's bowl.

Tuesday, March 26
This evening, the comet passes within 4 degrees
above Polaris, the North Star.

Wednesday, March 27
Comet 11 degrees upper left of Polaris at
nightfall, and 14 degrees below it before dawn on Thursday. Overnight,
Earth crosses comet's orbit plane, and we'll see the dust tail and thin
sheet of cometary particles edge-on, perhaps appearing as a very
narrow, bright line. March 28: Comet 11 degrees above "W" of
Cassiopeia at nightfall. Moon brighter each night until Full on April 3.

March 31-April 5
Comet Hyakutake within 2 to 6 degrees of the 2nd-
magnitude star Mirfak in Perseus. (Locate this star in NW, to upper left
of the "W" of Cassiopeia and upper right of Venus.) Starting April 5,
skies will once again be dark and moonless at nightfall.

Wednesday, April 3
At Abrams Planetarium, if skies are clear this evening, we are holding a
public viewing session for tonight's total lunar eclipse. The Moon will
rise in total eclipse right around sunset, but will probably remain
invisible in twilight until it begins to emerge from Earth's shadow at
7:53 p.m. EST. Our session will begin at 7:30 p.m., at the east end of
the top level of the parking ramp behind Abrams Planetarium (that's the
end farther from the Planetarium and closer to the Moon). While we're
waiting for the Moon to appear, we'll watch the early spring stars come
out, enjoy telescopic views of Venus in its "half moon" phase, binocular
views of Venus near the Pleiades star cluster, and of Comet Hyakutake.
The session will close with the Moon's complete emergence from
Earth's shadow at 8:59 p.m. EST.

April 6-24
Comet gets lower in NW each day at nightfall; look 22
degrees from Venus Apr. 6-13. If comet brightens enough as it
approaches the Sun, it might be seen in twilight for a few evenings past
April 24.

------ End of Abrams Planetarium Comet Hyakutake Diary ------

Diary by Bob Victor
Comet Finder Chart by David Batch
Diary and Chart made available over the Internet
by Jenny Pon, pon@dirac.pa.msu.edu